Add PHP index file

doc/index.php

@@ -0,0 +1,15 @@
+<?php
+
+/**
+ * index.php
+ *
+ * Redirects to the index.html file.
+ *
+ * @copyright &copy; 1999-2009 The SquirrelMail Project Team
+ * @license http://opensource.org/licenses/gpl-license.php GNU Public License
+ * @version $Id: index.php 12128 2007-01-13 20:15:44Z kink $
+ * @package squirrelmail
+ */
+
+header('Location: index.html');
+